Improvement in thread-tensions for sewing-machines



-P. EVENS; .lr.

Thread Tension for Sewing Machines. I No. 53,527. Patented March 27,1866.

"UNITED STATES PATENT 053912.

PLATT EVENS, JR, 013 cmonvnnrr, OHIO, ASSIGNOR To THE FLORENCE SEWINGMACHINE COMPANY, OF FLORENCE, MASSACHUSETTS.

IMPROVEMENT IN THREAD-TENSIONS FOR SEWING-MACHINES.

Specification forming part of Letters Patent No. 53,527, dated March 27,1866.

To all whom it may concern:

Be it known that I, PLATT EVENS, Jr., of Cincinnati, in the county ofHamilton and State of Ohio, have invented certain new and usefulImprovements in Thread-Tension Wheels or Surfaces for Sewing-Machinesand I do hereby declare the following to be a full, clear, and exactdescription of the same, reference being had to the accompanyingdrawings, making a part of this specification, in which- Figure 1represents an edge view of the wheel in question. Fig. 2 represents aside view thereof, and Fig. 3 represents a transverse section takencentrally through the tension-wneel.

To properly regulate the tension upon thread used in sewing-machines hasoccupied much thought and study, and many patents have been grantedtherefor; but a perfect threadtension is a matter yet to be discoveredor developed. There is another feature connected with the tension of thethread that causes much difficulty-via, preventing the slip or looseningup of the thread upon the tensionwheel when the thread is cut off at theend of the seam, which allows it to slack on the wheel, and until thisslack is all taken up again, when the machine or the sewing is againstarted, there will of course be irregular stitches made.

I am aware that appliances have been made to the tension-wheel toprevent this slipping or slacking up of the thread when out, and thatthey Succeed; but in some cases these appliances soon wear out, and inothers involve additions to the surface of the wheel where the threadwinds around that may be exceptionable in point of expense ordurability.

To avoid this slipping of the thread by the metallic surfaces of thewheel alone, and without any extraneous application to that surface, isthe object and purpose of my invention 5 and my invention consists inthe use of corrugated surfaces adjacent to each other, the projectionsupon one of the corrugated surfaces being oppositelthe depressions ofthe opposite corrugated Surface, so that the turn or turns of the threadaround the wheel shall have a zigzag instead of a regular circularcoil,and have many angular deflections, which hold it to the surfaces, andthus prevent the slipping or slackin g up when the thread is parted.

To enable others skilled in the art to make and use my invention, I willproceed to describe the same with reference to the drawlugs.

(t represents a hub of metal, having a suitable hole, I), through it forreceiving the shaft or journal, upon or with which the wheel is to turnas the thread is drawn to the sewingpoint. Upon the perimeter of thishub are secured the two flaring corrugated disks or flanges c, which maybe in closecontaot where they are joined to the hub, and flaring towardtheir perimeters for the easy reception of the thread, which has one,two, or more full turns around the wheel so made. The corrugations -erun radially from the center of the wheel,

and the projections on one of the flanges are placed opposite thedepressions of the other flange, so that a thread laid in between themand encircling the wheel shall have in it a series of angulardeflections and many points of impact with the corrugated surfaces,which prevent it from slipping when the thread is cut or parted.

The corrugations are put into the flanges, which are made of thin sheetmetal by means of dies, or, in other words, the flanges are stamped up,and thus cheaply made, and may be soldered or otherwise united to thehub a.

I am aware that the grooves in pulley or belt wheels have been roughenedso as to give more bite-upon the belt which partially encircles thepulley; but this I regard as involving a different construction, effect,and application, as the belt for a driving power is not presumed to beparted, and certainly is not cut, as the thread of a sewing-machine is,at the end of every seam; nor would the slacking of a driving-belt, ifit occurred, result in any such irregularity as is incident to theslacking of a thread in a sewing-machine; nor are the depressions of onecorrugated flange set opposite the projections of its mate or fellow, asI propose to attain the many deflections given to the thread laid orwound between the corrugated surfaces.

Having thus fully described my invention, what I claim is- Making andregulating tension in sewingrnaiohines by giving the thread a zigzagdirection in its turns around the tension-whee].

PLATT EVENS, JR. Witnesses:

J. H. WOODRUFF, SAML. BELLIs.

